Synthetic insecticides cause pollution to the environment. In addition, insects develop resistance toward them. So, there is an urgent need for effective safe alternatives. In the current study, nanoemulsion was prepared from essential oil of Cirtus sinensis by the ultrasonic method.  The efficacy of the nanoemulsion was evaluated against larvae of Culex pipiens and compared with that of the bulk emulsion. The mean droplet size of the nanoemulsion was 78.8±14.2 nm with poly dispersity index (PDI) value 0.28.   The LC₅₀ for the nanoemulsion and the bulk emulsion were 27.4 and 86.3 ppm, respectively related to Citrus sinensis essential oil. The Larvicidal activity of the formulated nanoemulsion was more toxic than that of bulk emulsion. The results showed that nanoemulsion of Cirtus sinensis EO can be used for control of vector-borne disease Culex pipiens larvae.